The invention is related to the field of nitride-based devices, and in particular to a wafer bonding technique for the fabrication of nitride-based devices.
Nitride-based transistors are playing a very important role in high frequency and high power electronics. The excellent intrinsic properties of nitride semiconductors such as large sheet charge density (˜1×1013 cm−2), high peak electron velocity (˜2.5×107 cm/s), high breakdown field strength (˜3 MV/cm) and good thermal conductivity (>1.5 W/cm·K) make them one of the best options for solid state power amplifiers, high voltage electronics, and high frequency transistors.
One important technology which can greatly improve GaN device performance as well as largely broaden its potential market and application is wafer bonding technology. In Si processing, wafer bonding has been a subject of interest for many years and it is now well developed as a basic technology both for integrated circuit (IC) and micro-electro-mechanical system (MEMS). However, in spite of its tremendous potential, the wafer bonding technology was scarcely studied in nitride semiconductors and there is very few information on using wafer bonding in GaN electronic applications.